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ABSTRACT: We extend the phase modulation method by in-plane diffractions from plane wave incidence to point source of surface plasmon polariton (SPP). A well-defined SPP focus is successfully realized from a point source under the diffraction by a carefully designed nanohole array, which is easy to layout in the future integrated optical circuits. With this method, the SPP Airy beam and finite plane wave are demonstrated as well, proving a general applicability of this modulation method. The proposed method and realized functions are expected of benefits for the future integration optics.
Optics Letters 12/2012; 37(24):5091-3. · 3.40 Impact Factor
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ABSTRACT: We worked out a new group of collimated plasmon beams by the means of
in-plane diffraction with symmetric phase modulation. As the phase type changes
from 1.8 to 1.0, the beam undergoes an interesting evolution from focusing to a
straight line. Upon this, an intuitive diagram was proposed to elucidate the
beam nature and answer the question whether they are nondiffracting or linear
focusing. Based on this diagram, we further achieved a highly designable scheme
to modulate the beam intensity (e.g., 'lossless' plasmon). Our finding holds
remarkable generality and flexibility in beam engineering and would inspire
more intriguing photonic designs.
11/2012;
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ABSTRACT: A coupled magnetic resonator waveguide, composed of a contacting gold nanosphere chain on a gold slab, is proposed and investigated. A broadband coherent magnetic plasmon mode can be excited in this one dimensional nanostructure. By employing the Lagrangian formalism and the Fourier transform method, the dispersion properties of the wave vector and group velocity of the magnetic plasmon mode are investigated. Small group velocity can be obtained from this system which can be applied as subwavelength slow wave waveguides.
Optics Express 11/2011; 19(24):23782-9. · 3.59 Impact Factor
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ABSTRACT: We report an experimental realization of a plasmonic Airy beam, which is generated thoroughly on a silver surface. With a carefully designed nanoarray structure, such Airy beams come into being from an in-plane propagating surface plasmon polariton wave, exhibiting nonspreading, self-bending, and self-healing properties. Besides, a new phase-tuning method based on nonperfectly matched diffraction processes is proposed to generate and modulate the beam almost at will. This unique plasmonic Airy beam as well as the generation method would significantly promote the evolutions in in-plane surface plasmon polariton manipulations and indicate potential applications in lab-on-chip photonic integrations.
Physical Review Letters 09/2011; 107(12):126804. · 7.37 Impact Factor
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ABSTRACT: Optical Airy beam, as a novel non-diffracting and self-accelerating wave
packet, has generated great enthusiasm since its first realization in 2007,
owing to its unique physics and exciting applications. Here, we report a new
form of this intriguing wave packet - plasmonic Airy beam, which is
experimentally realized on a silver surface for the first time. By particular
diffraction processes in a carefully designed nano-array structure, a novel
planar Airy beam of surface plasmon polariton (SPP) is directly generated and a
structural dependent phase tuning method is proposed to modulate the beam
properties. This SPP Airy beam is regarded as a two-dimensional (2D)
subwavelength counterpart of the 3D optical Airy beam in free space, allowing
for on-chip photonic manipulations. Moreover, it possibly suggests a
breakthrough in recognition of this unique wave packet in a polariton regime
after its previous evolution from free particle to pure optical wave.
05/2011;
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ABSTRACT: A resonance plasmon mode is formed between a gold nanorod and an infinite slab in infrared range, with local electric field enhancement factor over 40. A strong optical attractive force is exerted on the rod by the slab at resonance frequency. Based on Maxwell stress tensor method and numerical simulations, the optical force was calculated to be over 2.0 nN/(mW/μm2). For a fixed incident wavelength, the enhanced optical force is obtained only for the rods with particular length when the diameter is fixed. This strong optical force could be used as a possible selective optical trapping technique in the future.
Applied Physics Letters 02/2011; 98(8):083117-083117-3. · 3.84 Impact Factor
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ABSTRACT: We numerically investigated the magnetic plasmon resonances in double-rod and
triple-rod structures (DRSs and TRSs, respectively) for sensing applications.
According to the equivalent circuit model, one magnetic plasmon mode was
induced in the DRS. Due to the hybridization effect, two magnetic plasmon modes
were obtained in the TRS. Compared with the electric plasmon resonance in a
single-rod structure (SRS), the electromagnetic fields near the DRS and TRS
were much more localized in the dielectric surrounding the structures at the
resonance wavelengths. This caused the magnetic plasmon resonance wavelengths
to become very sensitive to refractive index changes in the environment medium.
As a result, a large figure of merit that is much larger than the electric
plasmon modes of SRS could be obtained in the magnetic plasmon modes of DRS and
TRS. These magnetic plasmon mode properties enable the use of DRSs and TRSs as
sensing elements with remarkable performance.
01/2011;
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ABSTRACT: We theoretically study a particular plasmonic structure with stereo nanoholes array in metallic film, which has remarkable abilities to manipulate the optical polarizations at optical frequencies. The main property is that any linear polarization states including a complete 90° optical rotation can be obtained in transmission by proper structural design in combination of enhanced transmission efficiency. Together with the polarization change, surface plasmon propagation bounded on the surface of transmission side also can be modulated. Furthermore, an analytical Coupled Mode Method (CMM) is developed by introducing a frequency dependent coupling coefficient to describe such optical rotation property in stereo plasmonic systems.
Optics Express 01/2011; 19(2):748-56. · 3.59 Impact Factor
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ABSTRACT: A one-dimensional diatomic meta-chain with equal-size holes and different-length slits is designed. Broadband coherent magnetic plasmon waves (MPW) are formed in such a system, excited by both the electric resonance in the slits and the magnetic resonance in the holes in a wide range of incidence angles (0°-40°) and broad frequency bands (200-230 THz). The dispersion properties of the MPW measured in our experiments agree with the theoretical calculation based on the Lagrange model. The coherent MPWs reported in this paper may have applications in subwavelength integrated nanocircuits.
Optics Express 12/2010; 18(25):26268-73. · 3.59 Impact Factor
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ABSTRACT: Loss is a crucial problem in plasmonic integrated optical circuits and metamaterials. The Er, Yb codoped gain material is introduced into a magnetic plasmon waveguide composed of a chain of nanosandwiches in order to solve the loss problem in such subwavelength waveguide. The magnetic plasmon mode and a higher order mode are chosen as the signal and pump light to enhance the radiation and pump efficiencies. The signal light propagating in the waveguide is investigated with different Er3+ doping concentration and signal decay time. It is shown that the gain effect can not only compensate the loss but also is able to amplify the signal, when exceeding certain threshold values of doping concentration and signal decay time. Comment: 9 pages, 4 figures
03/2010;
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ABSTRACT: This work investigates a kind of metallic magnetic cavity based on slit-hole resonators. Two orthogonal hybrid magnetic resonance modes of the cavity with a large spatial overlap are predesigned at the wavelengths of 980 and 1550 nm. The Yb:Er codoped material serving as a gain medium is set in the cavity; this enables the resonator to have a high optical activity. The numerical result shows that the strong lasing at 1550 nm may be achieved when the cavity array is pumped at 980 nm. This double resonance nanolaser array has potential applications in future optical devices and quantum information techniques.
Optics Letters 03/2010; 35(5):754-6. · 3.40 Impact Factor
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ABSTRACT: Simultaneously enhanced reflectance and transmittance greater than 35 dB are demonstrated for the lasing spaser (or spasing) behavior in an active fishnet metamaterial. In mimicking a lasing cavity, an equivalent active slab with Lorentz dispersion for the index of refraction is established to model the spasing metamaterial through the Fabry-Perot effect. Numerical and theoretical results show good agreement in the equal enhancement of reflectance and transmittance, as well as the non-monotonic dependence of the spasing intensity on the gain coefficient. In addition, directed emission of the spasing beam is verified numerically. Comment: 20papges, 5 figures, http://dsl.nju.edu.cn/mpp
12/2009;
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ABSTRACT: This paper investigates the radiation properties of two coupled split-ring resonators (SRRs). Due to electromagnetic coupling, two hybrid magnetic plasmon modes were induced in the structure. Our calculations show that the radiation loss of the structure was greatly suppressed by the hybridization effect. This led to a remarkable increase in the Q-factor of the coupled system compared to the single SRR. By adjusting the distance between the two SRRs, the Q-factor changed correspondingly due to different electromagnetic coupling strengths. This resulted in a coupled structure that functioned as a new type of nanocavity with an adjustable Q-factor. Comment: 7 figures, 3 tables. http://dsl.nju.edu.cn/mpp
09/2009;
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ABSTRACT: Magnetic resonance coupling between connected split ring resonators (SRRs) and magnetic plasmon (MP) excitations in the connected SRR chains were theoretically studied. By changing the connection configuration, two different coupling behaviors were observed, and therefore two kinds of MP bands were formed in the connected ring chains accordingly. From the extracted dispersion properties of MPs, forward and backward characteristics of the guided waves are well exhibited corresponding to the homo- and hetero-connected chains. Notably, thanks to the conductive coupling the revealed MP waves both have wide bandwidth even starting from the zero frequency. These results are suggested to provide instructions to build new kinds of subwavelength waveguides.
Optics Express 08/2009; 17(14):11486-94. · 3.59 Impact Factor
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ABSTRACT: We propose and analyze theoretically a double magnetic plasmon resonance nanolaser, in which Ytterbium-erbium co-doped material is used as the gain medium. Through design of the double magnetic resonance modes, pumping light (980nm) can be resonantly absorbed and laser light (1550nm) can be resonantly generated simultaneously. We introduce a set of rate equations combined to describe the operation of the laser and predict the lasing condition. According to our calculations, the disadvantage that pumping light is difficult to be absorbed by a thin slab of gain materials can be overcome. Comment: 13pages, 4 figures
03/2009;
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ABSTRACT: In this paper, we will propose that magnetic-resonance nanostructures in a metal surface could be used to realize extraordinary optical transmission (EOT). Toward this goal, we designed and fabricated a one dimensional diatomic chain of slit-hole resonator (SHR). Due to the strong exchange current interaction, a type of magnetic plasmon (MP) propagation mode with a broad frequency bandwidth was established in this system. Apparent EOT peaks induced by the MP mode were observed in our measured spectra at infrared frequencies. The strongest EOT peak was obtained at 1.07 eV with an incident angle of 20 degree. The measured dependence of EOT peaks on the incident angle coincided with the theoretical results quite well. This proposed MP propagation mode in SHR structure has good potential applications in multifrequency nonlinear optical processes.
03/2009;
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ABSTRACT: The magnetic plasmon (MP) modes in a metallic nanosandwich chain with a linearly increasing spacing along the chain has been investigated. Because of the graded coupling between nanosandwiches, the MP gradon with special field localization and large field amplitude can be found in the chain as well as the extended mode, which differs from the case of periodic chain. Using this property, we can precisely control the field in the chain and guide it to different ports at different frequencies, which works as a selective switch and may have potential application in integrated optics. Finally, we give out the underlying physical mechanism to help better understand and apply this graded chain.
Applied Physics Letters 12/2008; 93(23):233102-233102-3. · 3.84 Impact Factor
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ABSTRACT: We studied the propagation of an electromagnetic (EM) wave in a defective multilayer microcavity with an artificial magnetic atom located at the edge of the defect layer. When the frequency of the defect state is tuned to the resonance frequency of the magnetic atom, strong coupling happens between this atom and EM waves. It creates a type of magnetic plasmon polariton (MPP) with Rabi-type splitting effect that results in the two branches of the MPP mode. The linewidth of the MPP and Rabi-type oscillation of magnetic field inside the atom are investigated in the simulations. A great enhancement of local fields can also be obtained from the MPP, which has a good application in nonlinear optics.
Phys. Rev. B. 06/2008; 77(21).
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ABSTRACT: The propagation of microwaves through a chiral metamaterial based on a magnetic dimer is experimentally studied. As proposed by our previous theoretical model, two resonance peaks are obtained in the transmission spectrum; these originate from the hybridization effect of magnetic resonance modes in this system. Optical activity is also observed in the transmission wave. The polarization state dramatically changes around the resonance frequency: the transmitted wave becomes elliptically polarized with its major polarization axis approximately perpendicular to that of the linear incident wave. This coupled magnetic dimer system provides a practical method to optically design tunable active medium and device.
Applied Physics Letters 04/2008; 92(13):131111-131111-3. · 3.84 Impact Factor
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ABSTRACT: The magnetic plasmon (MP) modes in periodic chains of metallic trilayer nanostructures (nanosandwich) have been investigated numerically in optical frequency region. By employing the Fourier Transformation (FT) method, the MP modes excited in these chains can be observed directly.We have also used different exciting sources to excite the MP modes in the chain so that we can get clearer physics picture and richer information of the nanosandwich chain. For their long propagating lengths, the nanosandwich chains can well work as subwavelength waveguides to transport electromagnetic field. And one can easily tune the working frequencies and band width of the MP modes by changing the parameters of these chains.
Optics Express 04/2008; 16(6):3560-5. · 3.59 Impact Factor
